Pressure operated fastening means for containers

ABSTRACT

A pressure operated fastening means for container comprising hinged male and female halves, the male half comprising a cylindrical stub chamfered at its end portion and provided with hemispherical projections, which may be hollow or in the form of solid spherical pips, positioned generally midway between the head and the foot of the stub. The female half includes a circular ring of relatively greater thickness than the adjoining lateral wall, with insertion of the male half during fastening subjecting the projections to compression by the circular ring, with the projections upon further insertion forcing the relatively thinner lateral wall inwardly to effect the desired fastening.

United States Patent Padovani [54] PRESSURE OPERATED FASTENING MEANS FORCONTAINERS [72] Inventor: Pietro Padovani, Via A. Berardi 22,

Chievo, Verona, Italy [22] Filed: May8, 1970 211 App]. No.: 35,664

[30] Foreign Application Priority Data May 10, 1969 Italy ..61237 A/69[52] US. Cl ..292/76, 24/213, 24/216, 220/60, 292/17, 292/340, 292/D1G.38

[51] Int. Cl ..E05c 19/02, E05c 19/06 [58] Field of Search 292/D1G. 38;220/55 K, 60 R; 24/213 R, 213 B, 213

3,169,292 2/1965 Fenton ..24/213R 1 July 4,1972

3,219,374 11/1965 Snell ..292/15 R I FOREIGN PATENTS OR APPLlCATlONS641,668 2/1937 Germany ..292/77 Primary Examiner-Emest R. PurserAssistant Examiner-Robert L. Wolfe Attorney-Oberlin, Maky, Donnelly &Renner [57] ABSTRACT A pressure operated fastening means for containercomprising hinged male and female halves, the male half comprising acylindrical stub chamfered at its end portion and provided withhemispherical projections, which may be hollow or in the form of solidspherical pips, positioned generally midway between the head and thefoot of the stub. The female half includes a circular ring of relativelygreater thickness than the adjoining lateral wall, with insertion of themale half during fastening subjecting the projections to compression bythe circular ring, with the projections upon further insertion forcingthe relatively thinner lateral wall inwardly to effect the desiredfastening,

9 Claims, 6 Drawing Figures PRESSURE OPERATED FASTENING MEANS FORCONTAINERS The invention relates to a pressure-operated fastening meansfor containers comprising two hinged halves produced integrally with thefastening elements by vacuum moulding a thin sheet of thermoplasticmaterial. A pressure-operated fastening means similar to that to bedescribed is known in which the male element is connected to itssupporting base by means of a frusto-conical collar having a very sharptaper extending towards the foot of the male element, which collar hasto be compressed in this zone in the radial direction through the actionof one or more pips projecting from the body of the male element.

Also, the collar connecting the element to the base and the radialcompression of the foot of the male element permit axial movement of themale element when the force necessary for pressing one of the fasteningelements on to the other is applied to the male element, thus renderingit difficult to effect the fastening.

Because of their special rigidity and shape, the edges or lobes of thepips on the male element become worn by the walls of the female elementwhen they move into contact with each other during the closing andopening of the container.

Another type of pressure-operated fastening means is also known in whichthe male element is provided with projecting teeth which cooperate withtongues projecting from the female element.

The male and female elements are locked together as a result of thetongues bending under the action of the teeth, which tongues have toreturn to their normal position after the fastening has been effected.Such closure means, which necessitate the use of material having goodelastic properties are unable to stand up to repeated use, and have beenmade from P.V.C., polystyrol or the like sheet material. The main objectof the present invention is to provide fastening elements which resistthe tensile forces applied to them in opposite directions, withoutdeteriorating or flattening as a result of permanent deformation of oneor both fastening elements as a consequence of their being repeatedlyused even if the sheet material employed e.g. P.V.C., polystyrol and thelike does not possess a high degree of elasticity.

To achieve the object of the invention, there are provided on the femaleelement of the fastening means structures which resist compression whilebeing able to yield elastically, the elements projecting therefromhaving zones which cause the male element to yield elastically duringthe operations of locking the fastening elements together; the femaleelement also has elastically yielding portions for accommodating theprojecting elements when they pass from the compressed position to thenormal position in which the fastening is effected.

Some embodiments of the invention are illustrated, by way ofnon-limiting examples, on the attached sheet of drawings in which:

FIG. 1 is a plan view of the male element;

FIG. 2 is a side view of the male element;

FIG. 3 is a median section through the male and female elements prior totheir being locked together;

FIG. 4 is a section similar to the preceding one showing the phase inwhich the male element is compressed by part of the female element;

FIG. 5 is a section similar to that shown in FIG. 3 and FIG. 4, andshows the male and female elements during the phase in which the femaleelement is deformed as a result of pressure exerted by the male element;and

FIG. 6 is a side-elevation similar to that of FIG. 2 and showing a maleelement of different form from that seen in FIG. 2.

In the drawings, the same reference numerals are used for like orequivalent parts. It will be seen from FIGS. 1 and 3 that the maleelement projecting from the surface of a hinged half of the container issupported on a hollow frusto-conical base and is constituted by a hollowcylindrical stub 9, which is sharply chamfered at its end 10 which isclosed by a disc 1 1.

To simplify the description, this terminal portion 10 and the disc 11will hereinafter be referred to as the head of the male element, thepurpose of which is to facilitate insertion of the male element into thefemale element by virtue of the arrangement just described.

The female element comprises a frusto-conical hollow portion 16 having abase 18 and of a depth corresponding to the height of the male element.Said hollow portion communicates by way of a ring 17 with itsfrusto-conical support 15 which projects from the surface 14 of thehinged half of the container (see FIG. 3).

In the median and therefore particularly resilient zone 9 between thehead and the foot of the male element there are provided diametrallyopposed outwardly projecting hemispherical hollow elements 12, orspherical or spheroidal pips. When the male and female elements arebeing locked together, these projections come into contact with the ring17 which is of greater strength than the other portions of the femaleelement, so that the projections 12 are subjected to compression.

In this phase, the projections 12 do not suffer any deformation and thepressure applied to them pushes them in the direction of the medianlongitudinal axis of the zone 9. Consequently, the circular bases 12' ofthe projections 12, subjected to pressure, cause the side wall of thecylindrical stub 9 to curve inwards as can be clearly seen in FIG. 4.

This inward curvature of the portion 9 caused by the circular bases 12'of the projections 12 is of a completely elastic nature even if thematerial used is P.V.C., polystyrol or similar material, and it is dueto the resilience of the zone in which the projections 12 are locatedand to the circular line of their base 12'.

Practical tests have shown that the elastic inward curvature of the part9 does not cause any permanent deformation to the male element either atthe base or the apex of the projections 12. These tests have also shownthat the projections 12 do not cause any flattened portions on the ring17 of the female element because of their spherical surfaces and thearcuate crosssectional line of ring 17, so that the fastening meansremains efficient even after repeated use. This ring 17, the insidediameter of which corresponds approximately to the outside diameter ofthe part 9, applies pressure to the projections 12 on the part 9, whenthe male element is inserted into the female element, and the ring inturn undergoes slight elastic deformation caused by said projections 12.

The ring 17 is in fact subjected to slight stretching in the zonescorresponding to those extending over the element 9 between twosuccessive projections 12, and undergoes slight outward curvature atpoints corresponding to each projection 12.

It is obvious that the projections 12 will return to their normalpositions when those portions of the stub 9, previously inwardly curvedupon the passage of the projections 12 through the ring 17 acting as aclip-ring, resume their normal positions.

When the foot of the stub 9 and the ring 17 are positioned in the sameplane the fastening of the male to the female element is completed and,as can be seen from FIG. 4, the lateral wall 16 of the female elementwill assume an outward curvature 16' corresponding to the projections12, which curvature is facilitated by the thinness of the wall 16relatively to the ring 17, or by the particularly resilient zone of thefemale element Le. a zone located roughly half way along the length ofsaid element.

For the purpose of increasing the resistance of the male element tocurvature of its zone of maximum resilience, and in order to avoid anyaxial movement of the male element, ribs 13 extend from the base 12' ofeach projection 12 to the foot of the support 8 of the male element ascan be seen in FIGS. 1 to 6. Referring particularly to FIG. 6, it willbe seen that the male element illustrated therein because of its heightcan accommodate projections 12 and 12", of the kind previouslydescribed, which are located at different levels.

This feature enables a two-level fastening to be obtained which can beparticularly useful in some cases, and it is clear that thecorresponding female element will have to be of a height correspondingto that of the male element.

It will be obvious that any formal variations of a practical nature tothe subject-matter of the invention are to be considered as fallingwithin the scope of the invention covered by the following.

What is claimed is:

l. Pressure-operated fastening means for containers comprising twohinged halves, which closure means is produced integrally with thecontainer by vacuum moulding a thin sheet of thermoplastic material suchas polystyrol, P.V.C., and the like, said means being constituted by arecess contained in a hollow frusto-conical part projecting from thesurface of one half of the container, which recess adjoins a circularring having a thickness greater than the lateral wall of the recess andthan the lateral wall of the part constituting the support for thefemale element, the means also comprising a male element formed by ahollow cylindrical stub, which is sharply chamfered at its end portionand is closed by a circular disc and is located on a hollowfrusto-conical base projecting from the surface of the other half of thecontainer characterized in that hemispherical projections are providedon the male element at roughly midway between its head and foot, and inthat the female element is outwardly curved.

2. The fastening means of claim 1 wherein said hemispherical projectionsare hollow.

3. The fastening means of claim 1 wherein said hemispherical projectionscomprise spherical pips.

4. The fastening means according to claim 1, characterized in that thehemispherical projections are provided at diametrally opposite points onthe male element.

5. The fastening means according to claim 1, characterized in that thering connecting the female element to its frustoconical support is of athickness approximately equal to the maximum thickness of the half ofthe container.

6. The fastening means according to claim 1, characterized in that thethickness of the female element diminishes from the ring, joining it tothe support, towards its base.

7. The fastening means according to claim 1, characterized in that themale element has reinforcing'ribs extending from the base of eachhemispherical projection to the foot of the support of the male element.

8. The fastening means according to claim 1, characterized in that thehemispherical projections are aligned in a single plane.

9. The fastening means according to claim 1, characterized in that thehemispherical projections are disposed in at least two differentparallel planes.

1. Pressure-operated fastening means for containers comprising twohinged halves, which closure means is produced integrally with thecontainer by vacuum moulding a thin sheet of thermoplastic material suchas polystyrol, P.V.C., and the like, said means being constituted by arecess contained in a hollow frusto-conical part projecting from thesurface of one half of the container, which recess adjoins a circularring having a thickness greater than the lateral wall of the recess andthan the lateral wall of the part constituting the support for thefemale element, the means also comprising a male element formed by ahollow cylindrical stub, which is sharply chamfered at its end portionand is closed by a circular disc and is located on a hollowfrusto-conical base projecting from the surface of the other half of thecontainer characterized in that hemispherical projections are providedon the male element at roughly midway between its head and foot, and inthat the female element is outwardly curved.
 2. The fastening means ofclaim 1 wherein said hemispherical projections are hollow.
 3. Thefastening means of claim 1 wherein said hemispherical projectionscomprise spherical pips.
 4. The fastening means according to claim 1,characterized in that the hemispherical projections are provided atdiametrally opposite points on the male element.
 5. The fastening meansaccording to claim 1, characterized in that the ring connecting thefemale element to its frusto-conical support is of a thicknessapproximately equal to the maximum thickness of the half of thecontainer.
 6. The fastening means according to claim 1, characterized inthat the thickness of the female element diminishes from the ring,joining it to the support, towards its base.
 7. The fastening meansaccording to claim 1, characterized in that the male element hasreinforcing ribs extending from the base of each hemisphericalprojection to the foot of the support of the male element.
 8. Thefastening means according to claim 1, characterized in that thehemispherical projections are aligned in a single plane.
 9. ThEfastening means according to claim 1, characterized in that thehemispherical projections are disposed in at least two differentparallel planes.